A relatively new display system has been developed which generates images in all three physical dimensions. The system relies on the generation within a confined space, typically, a closed dome, of a volume upon which coherent light impacts to create the images. Each image is comprised of a number of light pixels (called voxels) usually generated by one or more laser beams impacting on the generated volume within the dome.
The defined volume can be created by spinning a helix shaped surface (disk) within the dome so that as the disk spins a volume is created defined by the disk surface as it moves up and down in a helical curve. Thus, at any point in time a different height of the volume is at a given physical location within the dome. A light spot can then be created by impacting a beam of coherent light with the disk at a particular point in time coinciding with the height desired for that point of light. By timing a large number of such light beams, three dimensional objects can be created within the dome and these objects then can be viewed from any position since the spinning disk (which creates the display volume) is essentially transparent to the eye. Such a system is the subject of U.S. patent application Ser. No. 07/409,176.
A number of problems become clear. It is desired to spin a physical object at 600 rpm. One problem is how to mount the disk. The simple solution, of course, is to mount it on a center shaft and use a motor to spin the disk to create the volume spacer. However, this will only allow images to be created at the outside edge of the disk.
One objective of the invention is the creation of a fully addressable display volume. A fully addressable display volume is a volume in which displays can be created anywhere within the space cylinder. Another objective is to create a very stable disk. A stable disk is one that does not have excessive dynamic movement over time and that does not have excessive vibration. A further objective is the ability to know precisely where any point on the disk is at any point in time.
Originally, a flat disk mounted on a shaft of a motor was used. It was found that air turbulence, vibration, and other aspects limited the resolution and the precision of such a display system.
Accordingly, there exists a need in the art for a rotational system that creates a fully addressable volume and which is dynamically stable and which lends itself to precise monitoring.